CN103331348A - Bending method for thin-walled steel pipe with rectangular section - Google Patents

Abstract

The invention provides a bending method for a thin-walled steel pipe with a rectangular section. Firstly, one end of the to-be-bent thin-walled steel pipe with the rectangular section is closed, the steel pipe is filled with quartz sand with the granularity of 10-20 meshes, and the other end of the steel pipe is closed after the quartz sand is compacted; then the to-be-bent part of the steel pipe is heated to the temperature 100-50 DEG C lower than the melting point of the material of the steel pipe, and the to-be-bent part of the steel pipe is bent on a die; after cooling, the steel pipe is taken down from the die, so that the bending work is finished. According to the bending method, the thin-walled steel pipe with the rectangular section is filled with fine and dense quartz sand which cannot lump at a high temperature so as to ensure that the interior of the steel pipe cannot deform during bending, and four side surfaces of the to-be-bent part of the steel pipe are restrained by the die so as to ensure that the exterior of the steel pipe cannot deform during bending, therefore, the aim that the cross section of the thin-walled steel pipe with the rectangular section cannot deform during the bending process is achieved.

Description

The bending method of a kind of square-section thin-wall steel tube

Technical field

The present invention relates to the Machining Technology field, be specially the bending method of a kind of square-section thin-wall steel tube.

Background technology

In field of machining, usually need straight steel pipe is bent to the shape of requirement.For the existing maturation process of the bending forming of circular cross-section steel pipe, but be the steel pipe of rectangle for the cross section, adopting conventional bending technology to carry out in the crooked process, because the special construction in its cross section can cause in crooked position generation situation as depicted in figs. 1 and 2:

1) a face active force that stretched when bending, its both sides be owing to there are two risers of c face and d face to support, and do not support in the middle of a face, and the mild steel good-extensibility, so a is towards concave deformation;

2) the b face acts on when bending by compression, and both sides are owing to have the c face and two risers supports of d face, middle not support, and b face below has bending mould to stop, whole material is extruded, under the extruding force effect, material is pressed against the inboard, makes b be out of shape towards fovea superior;

3) c, d two sides suitable two risers when bending vertically are bent, and existing bending has by compression, mainly are to stretch, because a, b two keep it vertical in the face of there is the stretching squeezing action on c, d two sides, it is bigger that it hinders bending force, can not guarantee after the bending that its face is vertical.

According to above three kinds of situation analysis, adopt present bending process when moment of flexure theory tee section straight steel pipe, can't avoid the distortion of bending section steel tube section.

Summary of the invention

The technical problem that solves

For solving the problem that prior art exists, the present invention proposes the bending method of a kind of square-section thin-wall steel tube.

Technical scheme

Technical scheme of the present invention is:

The bending method of described a kind of square-section thin-wall steel tube is characterized in that: adopt following steps:

Step 1: will treat crooked square-section thin-wall steel tube one end sealing, and in steel pipe, fill the quartz sand of full 10～20 order granularities, and with after the quartz sand compacting, the steel pipe other end be sealed;

Step 2: heat the bend position for the treatment of to steel pipe, be heated to treat that bend megadyne temperature degree is than low 100 ℃～50 ℃ of steel pipe material fusing point after, on mould, steel pipe is treated that the bend position carries out bending; And after cooling, steel pipe is taken off from mould, finish bending machining; Described mould treats that to steel pipe there is constraint four sides of bend position in BENDING PROCESS.

Beneficial effect

The present invention by in the thin-wall steel tube of square-section, fill fine and closely woven and high temperature under non-caking quartz sand, guaranteed that the inside of steel pipe is indeformable when crooked, and steel pipe is treated the constraint of four sides, bend position by mould, guaranteed the outside indeformable of steel pipe when crooked, thereby realized that the cross section in the thin-wall steel tube BENDING PROCESS of square-section is indeformable.

Description of drawings

Fig. 1: traditional handicraft schematic diagram;

Fig. 2: the sectional view after the traditional handicraft bending;

Fig. 3: structural representation of the present invention;

Fig. 4: the A-A cutaway view among Fig. 3

Fig. 5: rocking arm side view;

Fig. 6: rocking arm schematic diagram;

Fig. 7: die schematic diagram;

Wherein: 1, housing screw; 2, spacing support; 3, square-section thin-wall steel tube; 4, rotating shaft; 5, die; 6, cushion block; 7, rocking arm; 8, quartz sand.

The specific embodiment

Below in conjunction with specific embodiment the present invention is described:

The part that will process in the present embodiment is the case band, and the case carrying material is that No. 10 steel cross sections are 40*40, and four jiaos of R3 circular arcs, wall thickness are 2mm, requires to bend to the right angle of R50.During use at the outer surface of equipment.Its effect: 1. guarantee the equipment cavity shape.2. guarantee in transportation, to prevent that external force from colliding with.3. guarantee that the coordination of equipment profile is attractive in appearance.

Procedure of processing in the present embodiment is:

According to wanting the product processed image calculation to go out the length of run of part, intercept corresponding square-section thin-wall steel tube.Then thin-wall steel tube one end in square-section being used with steel tube section equal and opposite in direction, thickness is that the steel plate of 1～1.5mm seals with welding manner, thereby should the end sealing with steel pipe.In steel pipe, fill the quartz sand 8 of full 10～20 order granularities again, and quartz sand is tamped.Then the steel pipe other end is sealed with steel plate equally.To fill the square-section thin-wall steel tube of quartz sand at last and put into electric furnace, and treat crooked position and add, be heated to treat that bend megadyne temperature degree is than low 100 ℃～50 ℃ of steel pipe material fusing point after, on mould, steel pipe is treated that the bend position carries out bending.After cooling, steel pipe is taken off from mould, finish bending machining.In the present embodiment, treat that sweep is heated to 950 ℃～1000 ℃.

The mould that adopts in the present embodiment is made up of rocking arm 7, die 5, locating piece, cushion block 6 as shown in Figure 3.With reference to accompanying drawing 5 and accompanying drawing 6, rocking arm is " Y " type structure, and its top bifurcation structure is used for connecting die, and rocking arm is main force application part, and the material of employing is medium carbon steel, heat treatment HRC40～45.With reference to accompanying drawing 7, die is column structure, at the die edge trapezoidal groove is arranged, the groove floor width is identical with flexure plane width in the thin-wall steel tube of square-section to be processed, the outward-dipping angle in groove two sides is 1 °～3 °, both be convenient to after bending finishes, rectangular tube be taken out from groove, retrained the distortion of steel pipe two sides simultaneously again.The internal diameter of groove is identical with the crooked internal diameter of square-section to be processed thin-wall steel tube.Die also adopts medium carbon steel, heat treatment HRC40～45.The die center is connected with rocking arm bifurcation structure end coaxial rotation, and die is in the rocking arm bifurcation structure.Locating piece is used for square-section to be processed thin-wall steel tube one end is fixed, and steel pipe moves when preventing crooked the rotation.The cushion block pad had both transmitted bending force between square-section to be processed thin-wall steel tube excurvation curved surface and rocking arm bifurcation structure inner face, also retrain the outside distortion of steel pipe lateral surface, make tube bending after cylindrical straight smooth.

Claims (1)

1. the bending method of a square-section thin-wall steel tube is characterized in that: adopt following steps:

Step 1: will treat crooked square-section thin-wall steel tube one end sealing, and in steel pipe, fill the quartz sand of full 10～20 order granularities, and with after the quartz sand compacting, the steel pipe other end be sealed;

Step 2: heat the bend position for the treatment of to steel pipe, be heated to treat that bend megadyne temperature degree is than low 100 ℃～50 ℃ of steel pipe material fusing point after, on mould, steel pipe is treated that the bend position carries out bending; And after cooling, steel pipe is taken off from mould, finish bending machining; Described mould treats that to steel pipe there is constraint four sides of bend position in BENDING PROCESS.

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